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<li class="toctree-l2"><a class="reference internal" href="manpages.html">Man pages</a><ul>
<li class="toctree-l3"><a class="reference internal" href="manpages.html#library-files">(3) Library Files</a><ul>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl.html"><strong>SASL</strong> - SASL Authentication Library</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_authorize_t.html"><strong>sasl_authorize_t</strong> - The SASL authorization callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_auxprop.html"><strong>sasl_auxprop</strong> - How to work with SASL auxiliary properties</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_auxprop_add_plugin.html"><strong>sasl_auxprop_add_plugin</strong> - add a SASL auxiliary property plugin</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_auxprop_getctx.html"><strong>sasl_auxprop_getctx</strong> - Acquire an auxiliary property context</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_auxprop_request.html"><strong>sasl_auxprop_request</strong> - Request auxiliary properties from SASL</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_callbacks.html"><strong>sasl_callbacks</strong> - How to work with SASL callbacks</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_canon_user_t.html"><strong>sasl_canon_user_t</strong> - Application-supplied user canonicalization function</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_canonuser_add_plugin.html"><strong>sasl_canonuser_add_plugin</strong> - add a SASL user canonicalization plugin</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_chalprompt_t.html"><strong>sasl_chalprompt_t</strong> - Realm acquisition callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_checkapop.html"><strong>sasl_checkapop</strong> - Check an APOP challenge/response</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_checkpass.html"><strong>sasl_checkpass</strong> - Check a plaintext password</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_add_plugin.html"><strong>sasl_client_add_plugin</strong> - add a SASL client plugin</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_done.html"><strong>sasl_client_done</strong> - Cleanup function</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_init.html"><strong>sasl_client_init</strong> - SASL client authentication initialization</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_new.html"><strong>sasl_client_new</strong> - Create a new client authentication object</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_plug_init_t.html"><strong>sasl_client_plug_init_t</strong> - client plug‐in entry point</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_start.html"><strong>sasl_client_start</strong> - Begin an authentication negotiation</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_client_step.html"><strong>sasl_client_step</strong> - Perform a step in the authentication negotiation</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_decode.html"><strong>sasl_decode</strong> - Decode data received</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_decode64.html"><strong>sasl_decode64</strong> - Decode base64 string</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_dispose.html"><strong>sasl_dispose</strong> - Dispose of a SASL connection object</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_done.html"><strong>sasl_done</strong> - Dispose of a SASL connection object</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_encode.html"><strong>sasl_encode</strong> - Encode data for transport to authenticated host</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_encode64.html"><strong>sasl_encode64</strong> - Encode base64 string</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_encodev.html"><strong>sasl_encodev</strong> - Encode data for transport to authenticated host</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_erasebuffer.html"><strong>sasl_erasebuffer</strong> - erase buffer</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_errdetail.html"><strong>sasl_errdetail</strong> - Retrieve detailed information about an error</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_errors.html"><strong>sasl_errors</strong> - SASL error codes</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_errstring.html"><strong>sasl_errstring</strong> - Translate a SASL return code to a human-readable form</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getcallback_t.html"><strong>sasl_getcallback_t</strong> - callback function to lookup a sasl_callback_t for a connection</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getconfpath_t.html"><strong>sasl_getconfpath_t</strong> - The SASL callback to indicate location of the config files</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getopt_t.html"><strong>sasl_getopt_t</strong> - The SASL get option callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getpath_t.html"><strong>sasl_getpath_t</strong> - The SASL callback to indicate location of the mechanism drivers</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getprop.html"><strong>sasl_getprop</strong> - Get a SASL property</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getrealm_t.html"><strong>sasl_getrealm_t</strong> - Realm Acquisition Callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getsecret_t.html"><strong>sasl_getsecret_t</strong> - The SASL callback for secrets (passwords)</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_getsimple_t.html"><strong>sasl_getsimple_t</strong> - The SASL callback for username/authname/realm</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_global_listmech.html"><strong>sasl_global_listmech</strong> - Retrieve a list of the supported SASL mechanisms</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_idle.html"><strong>sasl_idle</strong> - Perform precalculations during an idle period</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_listmech.html"><strong>sasl_listmech</strong> - Retrieve a list of the supported SASL mechanisms</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_log_t.html"><strong>sasl_log_t</strong> - The SASL logging callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_add_plugin.html"><strong>sasl_server_add_plugin</strong> - add a SASL server plugin</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_done.html"><strong>sasl_server_done</strong> - Cleanup function</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_init.html"><strong>sasl_server_init</strong> - SASL server authentication initialization</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_new.html"><strong>sasl_server_new</strong> - Create a new server authentication object</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_plug_init_t.html"><strong>sasl_server_plug_init_t</strong> - server plug‐in entry point</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_start.html"><strong>sasl_server_start</strong> - Begin an authentication negotiation</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_step.html"><strong>sasl_server_step</strong> - Perform a step in the authentication negotiation</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_userdb_checkpass_t.html"><strong>sasl_server_userdb_checkpass_t</strong> - Plaintext Password Verification Callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_server_userdb_setpass_t.html"><strong>sasl_server_userdb_setpass_t</strong> - UserDB Plaintext Password Setting Callback</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_set_alloc.html"><strong>sasl_set_alloc</strong> - set the memory allocation functions used by the SASL library</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_set_mutex.html"><strong>sasl_set_mutex</strong> - set the mutex lock functions used by the SASL library</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_seterror.html"><strong>sasl_seterror</strong> - set the error string</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_setpass.html"><strong>sasl_setpass</strong> - Check a plaintext password</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_setprop.html"><strong>sasl_setprop</strong> - Set a SASL property</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_user_exists.html"><strong>sasl_user_exists</strong> - Check if a user exists on server</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_usererr.html"><strong>sasl_usererr</strong> - Remove information leak about accounts from sasl error codes</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_utf8verify.html"><strong>sasl_utf8verify</strong> - Verify a string is valid utf8</a></li>
<li class="toctree-l4"><a class="reference internal" href="reference/manpages/library/sasl_verifyfile_t.html"><strong>sasl_verifyfile_t</strong> - The SASL file verification</a></li>
</ul>
</li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="auxiliary_properties.html">Auxiliary Properties</a><ul>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#auxiliary-properties-and-the-glue-layer">Auxiliary Properties and the Glue Layer</a></li>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#passwords-and-other-data">Passwords and other Data</a></li>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#sasldb">sasldb</a></li>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#ldapdb">ldapdb</a></li>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#sql">sql</a></li>
<li class="toctree-l3"><a class="reference internal" href="auxiliary_properties.html#user-canonicalization">User Canonicalization</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="authentication_mechanisms.html">Authentication Mechanisms</a><ul>
<li class="toctree-l3"><a class="reference internal" href="authentication_mechanisms.html#mechanisms">Mechanisms</a><ul>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#anonymous">ANONYMOUS</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#cram-md5">CRAM-MD5</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#digest-md5">DIGEST-MD5</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#external">EXTERNAL</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#g2">G2</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#gssapi">GSSAPI</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#gss-spegno">GSS-SPEGNO</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#kerberos-v4">KERBEROS_V4</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#login">LOGIN</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#ntlm">NTLM</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#otp">OTP</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#passdss">PASSDSS</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#plain">PLAIN</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#scram">SCRAM</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#srp">SRP</a></li>
<li class="toctree-l4"><a class="reference internal" href="authentication_mechanisms.html#non-sasl-authentication">Non-SASL Authentication</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="authentication_mechanisms.html#summary">Summary</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="pwcheck.html">Pwcheck</a><ul>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#auxprop">Auxprop</a></li>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#auxprop-hashed">Auxprop-hashed</a></li>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#saslauthd">Saslauthd</a></li>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#authdaemon">Authdaemon</a></li>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#alwaystrue">Alwaystrue</a></li>
<li class="toctree-l3"><a class="reference internal" href="pwcheck.html#auto-transition">Auto Transition</a></li>
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<li class="toctree-l2"><a class="reference internal" href="faq.html">Frequently Asked Questions</a><ul>
<li class="toctree-l3"><a class="reference internal" href="faqs/authorize-vs-authenticate.html">What is the difference between an Authorization ID and a Authentication ID?</a></li>
<li class="toctree-l3"><a class="reference internal" href="faqs/crammd5-digestmd5.html">Why do CRAM-MD5 and DIGEST-MD5 not work with CyrusSaslauthd?</a></li>
<li class="toctree-l3"><a class="reference internal" href="faqs/openldap-sasl-gssapi.html">How do I configure OpenLDAP +SASL+GSSAPI?</a></li>
<li class="toctree-l3"><a class="reference internal" href="faqs/plaintextpasswords.html">Why does CyrusSasl store plaintext passwords in its databases?</a></li>
<li class="toctree-l3"><a class="reference internal" href="faqs/rfcs.html">RFCs and drafts</a></li>
<li class="toctree-l3"><a class="reference internal" href="faqs/upgrade-saslv2.html">Why am I having a problem running dbconverter-2 to upgrade from SASLv1 to SASLv2?</a></li>
</ul>
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<li class="toctree-l2"><a class="reference internal" href="resources.html">Other Documentation & Resources</a></li>
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<li class="toctree-l1"><a class="reference internal" href="../developer.html">Developers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="appconvert.html">Converting Applications from v1 to v2</a><ul>
<li class="toctree-l3"><a class="reference internal" href="appconvert.html#tips-for-both-clients-and-servers">Tips for both clients and servers</a></li>
<li class="toctree-l3"><a class="reference internal" href="appconvert.html#tips-for-clients">Tips for clients</a></li>
<li class="toctree-l3"><a class="reference internal" href="appconvert.html#tips-for-servers">Tips for Servers</a></li>
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<li class="toctree-l2"><a class="reference internal" href="developer/programming.html">Application Programmer’s Guide</a><ul>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#introduction">Introduction</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#about-this-guide">About this Guide</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#what-is-sasl">What is SASL?</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#background">Background</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#how-did-the-world-work-before-sasl">How did the world work before SASL?</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#sasl-to-the-rescue">SASL to the rescue!</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#briefly">Briefly</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#what-is-the-cyrus-sasl-library-good-for">What is the Cyrus SASL library good for?</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#what-does-the-cyrus-sasl-library-do">What does the Cyrus SASL library do?</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#what-doesn-t-the-cyrus-sasl-library-do">What doesn’t the Cyrus SASL library do?</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#client-only-section">Client-only Section</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#a-typical-interaction-from-the-client-s-perspective">A typical interaction from the client’s perspective</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#how-does-this-look-in-code">How does this look in code</a></li>
</ul>
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<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#server-only-section">Server-only Section</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#a-typical-interaction-from-the-server-s-perspective">A typical interaction from the server’s perspective</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#id1">How does this look in code?</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#common-section">Common Section</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#callbacks-and-interactions">Callbacks and Interactions</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#security-layers">Security layers</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#example-applications-that-come-with-the-cyrus-sasl-library">Example applications that come with the Cyrus SASL library</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#sample-client-and-sample-server"><cite>sample-client</cite> and <cite>sample-server</cite></a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#cyrus-imapd-v2-1-0-or-later">Cyrus imapd v2.1.0 or later</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#imtest-from-cyrus-2-1-0-or-later"><cite>imtest</cite>, from Cyrus 2.1.0 or later</a></li>
</ul>
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<li class="toctree-l3"><a class="reference internal" href="developer/programming.html#miscellaneous-information">Miscellaneous Information</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#empty-exchanges">Empty exchanges</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/programming.html#idle">Idle</a></li>
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</ul>
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<li class="toctree-l2"><a class="reference internal" href="developer/plugprog.html">Plugin Programmer’s Guide</a><ul>
<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#introduction">Introduction</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#about-this-guide">About this Guide</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#what-is-sasl">What is SASL?</a></li>
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<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#common-section">Common Section</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#overview-of-plugin-programming">Overview of Plugin Programming</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#use-of-sasl-utils-t">Use of sasl_utils_t</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#error-reporting">Error Reporting</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#memory-allocation">Memory Allocation</a></li>
<li class="toctree-l4"><a class="reference internal" href="developer/plugprog.html#client-send-first-server-send-last">Client Send First / Server Send Last</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#client-plugins">Client Plugins</a></li>
<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#server-plugins">Server Plugins</a></li>
<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#user-canonicalization-canon-user-plugins">User Canonicalization (canon_user) Plugins</a></li>
<li class="toctree-l3"><a class="reference internal" href="developer/plugprog.html#auxiliary-property-auxprop-plugins">Auxiliary Property (auxprop) Plugins</a></li>
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</li>
<li class="toctree-l2"><a class="reference internal" href="developer/testing.html">Testing</a><ul>
<li class="toctree-l3"><a class="reference internal" href="developer/testing.html#testing-the-cmu-sasl-library-with-the-included-sample-applications">Testing the CMU SASL Library with the included sample applications</a><ul>
<li class="toctree-l4"><a class="reference internal" href="developer/testing.html#example">Example</a></li>
</ul>
</li>
<li class="toctree-l3"><a class="reference internal" href="developer/testing.html#running-the-testsuite-application">Running the Testsuite application</a></li>
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<li class="toctree-l1"><a class="reference internal" href="../support.html">Support/Community</a></li>
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<p class="caption"><span class="caption-text">IMAP</span></p>
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<li class="toctree-l1"><a class="reference external" href="http://www.cyrusimap.org">Cyrus IMAP</a></li>
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<li>Concepts</li>
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<div class="section" id="concepts">
<h1>Concepts<a class="headerlink" href="#concepts" title="Permalink to this headline">¶</a></h1>
<div class="section" id="sasl">
<h2>SASL<a class="headerlink" href="#sasl" title="Permalink to this headline">¶</a></h2>
<p>Simple Authentication and Security Layer (SASL) is a protocol developed by the Internet Engineering Task Force (IETF) for the purpose of providing an extensible and pluggable authentication framework, primarily for non-web related protocols. It is commonly used in email related protocols, such as SMTP, IMAP, and POP, along with XMPP, LDAP, and a few others. In doing so, various implementations of those protocols, such as the Cyrus IMAP or Dovecot servers, can support a wide range of authentication mechanisms with various email clients which implement the IMAP protocol, including Thunderbird, Outlook, and the Android mail client.</p>
<p>RFC 4422 is the base framework specification for SASL. It provides guidance for protocol designers, server software implementations, and SASL mechanism designers. Protocol definitions, and SASL mechanism specifications in turn make use of this framework to independently support each other. That is, if a protocol were designed 5 years ago to make use of SASL, and a new mechanism were designed today, server implementations and client software could make use of that new mechanism without a change to the original server protocol spec.</p>
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<div class="section" id="sasl-authentication-mechanisms">
<h2>SASL Authentication Mechanisms<a class="headerlink" href="#sasl-authentication-mechanisms" title="Permalink to this headline">¶</a></h2>
<p>SASL mechanisms are plugable authentication methods that are developed independently of server protocols. For example, the Generic Security Service Application Program Interface (GSSAPI) mechanism, defined in RFC 4752, defines a network oriented protocol for authenticating a client to a server, using Kerberos version 5, a trusted 3rd party ticket based system. The GSSAPI mechanism should work with all clients and servers which implement support for it, regardless of the actual server protocol used (such as IMAP), given the protocol was designed for use with the SASL framework.</p>
<p>A list of developed SASL mechanisms can be found at the <a class="reference external" href="http://www.iana.org/assignments/sasl-mechanisms/sasl-mechanisms.xml">IANA registered SASL mechanisms</a> page. A more detailed discussion of these mechanisms can be found in <a class="reference internal" href="authentication_mechanisms.html"><span class="doc">Authentication Mechanisms</span></a>.</p>
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<div class="section" id="security-layers">
<h2>Security Layers<a class="headerlink" href="#security-layers" title="Permalink to this headline">¶</a></h2>
<p>SASL Security Layers allow a server and client to negotiate integrity and confidentiality protection for a connection once it has been authenticated. It is only available for mechanisms which themselves are capable of providing such protection (such as GSSAPI). It is capable of being used to encrypt a connection over the public internet, and can be used as an alternative to TLS encryption.</p>
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<div class="section" id="channel-binding">
<h2>Channel Binding<a class="headerlink" href="#channel-binding" title="Permalink to this headline">¶</a></h2>
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<div class="section" id="realms">
<h2>Realms<a class="headerlink" href="#realms" title="Permalink to this headline">¶</a></h2>
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<div class="section" id="protocols">
<h2>Protocols<a class="headerlink" href="#protocols" title="Permalink to this headline">¶</a></h2>
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<div class="section" id="cyrus-sasl">
<h2>Cyrus SASL<a class="headerlink" href="#cyrus-sasl" title="Permalink to this headline">¶</a></h2>
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<div class="section" id="the-glue-library">
<h2>The Glue Library<a class="headerlink" href="#the-glue-library" title="Permalink to this headline">¶</a></h2>
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<div class="section" id="auxiliary-properties">
<h2>Auxiliary Properties<a class="headerlink" href="#auxiliary-properties" title="Permalink to this headline">¶</a></h2>
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<h2>Plugins<a class="headerlink" href="#plugins" title="Permalink to this headline">¶</a></h2>
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